Ah idont know about a concorde having 19s on it but u can defintely try it, i would recommend going any bigger than that though bc it will defintely kill you on mpg. 19's will probably fit, u might wanna get it checked out at a shop though

Go to superbuytires.com or tirerack.com and they have a sizing chart that will tell you how big of rims you can put on it. I'd say the size next to the biggest will be the size that you can fit on there without any mods.